Study Identifies Hypothyroidism Among Patients Taking Sunitinib
Abnormal thyroid function is common among patients with metastatic renal cell carcinoma taking a new drug called sunitinib, and these patients' thyroid levels should be routinely monitored, a new study finds.
Sunitinib was recently approved for the treatment of advanced renal cell carcinoma. A common side effect of the drug is fatigue, and abnormal thyroid function can cause weakness and fatigue. Brian I. Rini, M.D., of the Cleveland Clinic Taussig Cancer Center, and colleagues decided to measure thyroid function in patients taking sunitinib. They reviewed medical records of 66 patients treated in clinical trials of the drug for whom thyroid function tests were available. Fifty-six (85 percent) of the patients had one or more thyroid function blood test abnormalities, and 47 of those patients had clinical signs or symptoms of hypothyroidism.
In 17 patients, doctors attempted to correct the hypothyroidism using thyroid replacement hormones, and symptoms improved in 9 of those patients. Routine monitoring of thyroid function blood tests is warranted in patients with renal cell carcinoma taking sunitinib, the authors conclude.